Conjugated dienes, such as butadiene, present intriguing possible sources of a variety of more valuable chemicals, intermediates, and end-products. Such unsaturated compounds, obtained from various sources such as the conversion of or extraction from refinery streams produced in the modern integrated refinery and chemical processing operation sometimes terms a petrocomplex are still relatively cheap chemicals and upgrading thereof has economic advantages.
A number of oxidation processes have been developed using a variety of catalyst systems for the conversion of conjugated dienes, particularly acyclic conjugated dienes, to diesters (diacyloxyolefin).
Further needed, to provide economic viability for such processes, are methods for the recovery of the oxidation catalyst in a form or condition suitable for recycle and thus reuse in the oxidation step.